In an Alfa again!
Join Date: Jun 2012
Location: South Africa
Hot air through the dash vents.
Well, here's another fix for you.
I had a failed heater control valve that was allowing the heater to be slightly on when in the off position. I replaced the valve and was a bit dissapointed when there was still a bit of heat coming through when the engine was really hot.
Found the source.
There is a seal at the rear of the engine bay that seals up against the underside of the bonnet when closed. If this seal is old and a bit flat (rather like me!) hot air leaks out of the engine bay and into the cold air inlet just in front of the windsdcreen.
Either replace the seal, (expensive) or use a length of self adhesive neoprene weather seal on the underside of the bonnet to close the gap. I use a length of 25mm x 6mm and it was ideal.
Result:- Cool air through the air vents in the fiercest of South Africa's heat, ands a more effective airconditioning.